The reason why the science exists is because not everything has been discovered and described in theories yet; thanks to this fact the scientists can research. This also means that there are things that even “the philosophers haven't dreamed of”. Regardless of whether we believe it or not, the phenomena exists and it does not care about our ignorance or beliefs.

In the past the people believed that the Earth is flat, that the Sun orbits the Earth, that an object heavier then the air cannot fly, etc. People who were saying that it is not true and it works in a different way were believed to be unwise (they also were persecuted). Nevertheless, the phenomenas didn't care about what people were thinking, they just existed, they were functioning the way that they were created according to the laws ruling the universe. People didn't know these laws so they were saying that such things were impossible.

Exactly the same happens in the present time, people don't believe something that they don't know. Once they get to know something, they change their thinking. This is neither good nor bad, this is the human attitude to things that deny their beliefs. Inedia or even long fasting are not exceptions to this.

It is a fact that since the beginning of the human civilization on the Earth there were, are and will be people who did, do, will not need to eat. So this means that since there were, are and will be such people, then potentially every human is able live completely without food. Of course, a potential does not automatically mean a skill, because it has to be drilled if one decides so.